Vibratory compactor



June 23, 1970 o. OLSEN 3,516,341

VIBRATORY COMPACTOR Filed March 18, 1968 I as 50 5 25 47 LAWRENCEQOLSENINVENTOR BUCK/105W, BLORE, KLAROU/ST 8 SPAR/(MAN ATTORNEYS United StatesPatent Office 3,516,341 Patented June 23, 1970 3,516,341 VIBRATORYCOMPACTOR Lawrence O. Olsen, Portland, Oreg., assignor to HysterCompany, Portland, Oreg., a corporation of Nevada Filed Mar. 18, 1968,Ser. No. 713,646 Int. Cl. E01c 19/24 U.S. CI. 94-50 16 Claims ABSTRACTOF THE DISCLOSURE A vibratory compactor in which a roller is connectedto the compactor frame by vibration isolator elements at least one ofwhich at each end of the roller resists roller vibrations longitudinallyof the frame in tension and compression and vertically in shear. Theroller is journaled on a shaft which connects the drum to the frame andwhich carries eccentric weights which induce the roller vibrations. Theshaft is journaled to the frame for rotation about an axis which iseccentric with respect to the axis of rotation of the drum in adirection limiting the amplitude of vibration forced upon the frame bythe drum.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to earth compaction equipment and more particularly to avibratory earth compaction roller.

Description of the prior art In vibratory compactors of the prior art,elastomer isolator blocks connect the vibratory roller drum to thecompactor frame in a manner so as to resist drum vibrations bothlongitudinally and vertically in shear only, thereby providing maximumfreedom of movement of the roller relative to the frame and thus optimumisolation of the frame and drive components from roller vibration.However, it has been found that the use of such an isolator arrangementpermits so much longitudinal movement of the drum with respect to thecompactor frame, especially with heavy rollers, that isolators failprematurely. Furthermore, scrapers connected to the compactor frame andused to remove soil from the drum surface become badly damaged when setclosely enough to the drum to operate efiiciently, and the drum sagsexcessively when the roller is lowered down a steep embankment.

SUMMARY OF THE INVENTION The problems as described above with respect tothe prior art have been overcome with the compaction roller of thepresent invention through the provision of isolator means arrangedbetween the roller drum and frame in a manner to resist longitudinalmovements of the roller at least partially in tension and compressionrather than solely in shear so as to restrict the amplitude of movementbetween the roller and frame in that direction while still resistingvertical movement of the roller solely in shear for maximum freedom ofmovement of the roller in its compacting effort. The resulting reductionin the degree of isolation of longitudinal roller movement from theframe is compensated for by an eccentric positioning of the rotationalaxis of the drum shaft with respect to the rotational axis of the rollerdrum on such shaft in a manner which limits the amplitude of vibrationforced upon the frame.

Accordingly, primary objects of the present invention are to provide:

(1) A vibratory roller with an improved isolator arrangement forincreased isolator life;

(2) An improved isolator arrangement for a vibratory roller which limitsthe movement of the drum relative to the frame in the direction oftravel to permit proper adjustment of scrapers with respect to the drumwhile maintaining a clearance between the scrapers and drum, and toresist sag of the drum relative to the frame when operating on steepinclines, without restricting the freedom of movement between the drumand frame in a vertical direction;

(3) A vibratory roller with an isolator arrangement as aforesaidcombined with means for reducing the amplitude of vibration forced uponthe frame to offset the reduced effective isolation of vibrationlongitudinally of the frame; and

(4) A vibratory roller with means for varying the eccentricity betweenthe rotational axis of the roller and the rotational axis of the shaftwhich drives the eccentric weight means to compensate for changes in theamplitude of vibration forced upon the frame by the roller.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects andadvantages of the present invention will become more apparent from thefollowing detailed description which proceeds with reference to theaccompanying drawing, wherein:

FIG. 1 is a side elevational view of a vibratory compaction roller inaccordance with the present invention;

FIG. 2 is a top plan view of the roller of FIG. 1 with a portion of theroller drum broken away for clarity of illustration;

FIG. 3 is a partial sectional view of a modified drum isolator mountingin accordance with the invention;

FIG. 4 is a partial horizontal sectional view showing anothermodification of drum isolator mounting which is adjustable; and

FIG. 5 is a vertical sectional view taken along the line 55 of FIG. 4.

DETAILED DESCRIPTION With reference to the drawings, FIGS. 1 and 2 showa vibratory compactor 10 including a ground-engaging cylindrical drumroller 12 connected at its opposite ends by a shaft 14 to oppositelongitudinal side frame members 16, 17 of a compactor frame 1 8. Frame18 is adapted to be towed by a tractor vehicle (not shown) connected tothe frame at a hitch 20. A telescoping leg 22 is also provided tosupport the front end of the frame above the ground surface whendisconnected from a tractor as shown.

An internal combustion engine 24 is mounted on the frame forwardly ofthe roller and transmits rotary power through a drive shaft 26 and gearbox 28 to the shaft 14 to rotate the shaft independently of the drum.Shaft 14 mounts eccentric weights 30 and 31 which rotate with the shaftand with centers of gravity offset on the same side of the axis 32 ofthe main portion of the shaft to serve as a vibration generator means.Roller drum 12 is journaled to the main portion of shaft 14 at internalbearings 34, 35 supported by internal drum webs 37, 38, respectively, torotate independently of the shaft about axis 32. Thus upon rotation ofshaft 32 counterweights 30, 31 transmit vibrations through drum 12 tothe surface under compaction.

Opposite ends 40, 41 of drum shaft 14 are journaled in bearings 43, 44within hub portions 46, 47 of journal support members 49, 50. Eachsupport member includes a pair of longitudinal support arms 52, 53extending in opposite longitudinal directions from the central hubthereof. The outer ends of the support arms are connected by elastomerisolator members 55, 56 to opposite side frame members 16, 17 to isolatethe frame and supported drive components from vibrations of roll er drum12.

Additional details of general construction of the roller drum and itsmounting and isolators are illustrated and described, for example, inthe prior copending application of Jack B. Peterson, Ser. No. 642,586,filed May 31, 1967 for Vibratory Compactor. However, in prior artconstructions, as shown for example in the aforementioned copendingapplication Ser. No. 642,586, both of the isolators at each end of thedrum are connected to the frame in the manner shown with respect toisolator 55, with the isolator extending between and connected tolongitudinally extending faces of the frame and support arm so that bothvertical and longitudinal vibrations of the drum are resisted by theisolator wholly in shear. Such an arrangement provides for maximumfreedom of movement of the drum relative to the frame and thus maximumisolation of the frame, while also providing maximum resistance tomovement of the drum in compression and tension transversely of the sideframe members.

Contrary to prior constructions, the illustrated compactor has its rearisolator 56 at each end of the drum mounted to an outer support armportion 58 and a parallel frame portion 59 which extend transversely ofthe side frame members and parallel to the drum axis so as to resistvibrations of the drum longitudinally of the frame, in tension andcompression rather than in shear, while still resisting verticalvibrations in shear only. Isolators 55 and 56 at both ends of the drumare mounted in exactly the same manner.

The effect of the illustrated isolator mounting is to restrictlongitudinal movements of the roller relative to the frame while stillpermitting maximum freedom of vertical movement of the drum relative tothe frame as needed for optimum compaction with minimum transfer ofvibration to the frame.

With the foregoing isolator arrangement, there would be the possibilitythat excessive vibration could be transferred to the frame in thelongitudinal direction were it not for the provision of means forlimiting the amplitude of vibration forced upon the frame by the roller.To this end, the opposite ends 40, 41 of shaft 14 journaled in bearings43, 44 are offset from the intermediate main portion of the shaft toprovide the shaft with an axis of rotation 62 which is eccentric withrespect to the axis of rotation 32 of the drum. Shaft axis 62 is offseton the same side of drum axis 32 as are the centers of gravity ofeccentric Weights 30, 31. Thus upon rotation of shaft 14 theeccentricity of the main body of the shaft and drum on one side of therotational axis 62 will counteract to some extent the eccentricity ofthe weights 30, 31 on the opposite side of axis 62 to restrict theamplitude of vibration forced upon journal support members 49, 50 of theframe.

With the amplitude of movement between the roller and the frameeffectively limited as aforesaid at least in the longitudinal direction,drum scrapers 64, 65, which are adjustably bolted to the frame forremoving soil from the surface of the drum, can be mounted with theirblades close enough to the drum surface for effective cleaning withoutthe drum slamming against the blades on uneven ground or on a steepincline. Moreover, isolator life is increased through reduction of thelongitudinal amplitude of movement between the roller and frame, andrearward sag of the roller relative to the frame is minimal when thecompactor is backed down or towed up a steep embankment.

Although longitudinal movement of the roller in FIG. 2 is limitedthrough placement of the rear isolators to resist such movement solelyin tension and compression, this is not necessary so long as at leastone isolator element has at least a tensile and compressive component ofresistance to vibration in the longitudinal direction. Thus in FIG. 3 amodified drum connection for a drum 12a and shaft 14a with eccentricweight 30a includes an eccentric shaft end 40a journaled in bearing 43aof a modified journal support structure 49a. Journal support 49a has arearwardly extending support arm 70 with an outer isolator mountingflange 72 extending at an oblique angle with respect to side framemember 16a and the drum axis, and parallel to an oblique isolatormounting flange 74 on side frame member 16a. An isolator member 76 joinssupport flange 72 and frame flange 74 so as to resist longitudinalvibrations of the drum partly in shear and partly in tension andcompression. A second isolator 55a' joins a forward support arm 78 ofsupport member 49a to the frame in the usual manner so as to resistlongitudinal vibrations wholly in shear. Both of isolators 55a and 76resist vertical vibrations in shear only like the isolators of FIG. 2.

Referring to FIGS. 4 and 5, a modified drum shaft 14b is provided withan eccentric shaft end 40b which can be adjusted relative to the mainbody of the shaft to vary the eccentricity of the rotational axis 62a ofthe shaft relative to the rotational axis 32a of the drum. For thispurpose, shaft end 40b is journaled in bearing 43b and includes a flangeportion 80 joined by bolts 81, 82 to an abutting flange end 84 of themain body 14b of the shaft. Flange 80 is provided with slots 86, 87through which bolts 81, 82 extend to permit, when the bolts areloosened, sliding adjustment of shaft end 40b relative to shaft body1412. Adjustment of the eccentricity of the shaft axis is desirable tocompensate for the effect of varying the mass of the drum or eccentricweights or the eccentricity of such weights. The eccentricity of theweights could be varied if desired in a manner, for example, similar tothat by which the eccentricity of the shaft is varied.

The drum scrapers of prior compactors would be set quite close to thedrum surface on even ground, but upon encountering uneven rocky ground,the scrapers would be damaged by the pounding of the drum against thescrapers. This problem has been eliminated by the isolator arrangementand shaft mounting of the present invention.

Although in the illustrated embodiments, one isolator is arranged withits vertical shear planes at an angle to the vertical shear planes ofthe other isolator at the same end of the drum, such an arrangement isnot absolutely necessary. For example both isolators 55, 56 of FIG. 2could be arranged with their vertical shear planes extending parallel tothe axis of the drum in the orientation of isolator 56. Alternatively,both isolators could be arranged with their vertical shear planesoblique to the axis of the drum in the orientation of isolator 76 inFIG. 3. However, the illustrated arrangements are preferred since thelast-mentioned alternatives, and particularly the one mentioned withrespect to FIG. 2, could result in excessive axial movement of theroller drum transversely of the frame. Although the shaft ends 40, 41are illustrated as being enlarged with respect to the mam body of shaft14 for clarity of illustration of their eccentricity, in practice theseends are of reduced diameter relative to the main body of the shaft asshown in the aforementioned prior copending application. Thus inmanufacturing the shafts, the eccentricity of the shaft ends can bemachined into the shaft.

Having illustrated and described several preferred embodiments of theinvention, it should be apparent to those skilled in the art that thesame permits of modification in arrangement and detail. I claim as myinvention all such modifications as come within the true spirit andscope of the following claims.

I claim:

1. A vibratory compactor including:

a frame having a longitudinal dimension in the direction of travel ofsaid compactor,

a roller having an axis of rotation extending transversely within saidframe,

vibrations generating means connected to said roller for vibrating saidroller,

an isolator means connecting the opposite ends of said roller to saidframe so as to isolate the frame from the vibrations of said roller,

said isolator means resisting vibrations of said roller in a directionnormal to said axis of rotation and longitudinally of said frame atleast partially in tension and compression,

said isolator means resisting vertical vibrations of. said roller inshear in a manner such that vertical vibrations of said roller areresisted to a lesser degree by said isolators than longitudinalvibrations thereof.

2. A vibratory compactor including:

a frame having a longitudinal dimension in the direction of travel ofsaid compactor,

a roller having an axis of rotation extending transversely within saidframe,

vibrations generating means connected to said roller for vibrating saidroller,

and isolator means connecting the opposite ends of said roller to saidframe so as to isolate the frame from the vibrations of said roller,

said isolator means resisting vibrations of said roller in a directionnormal to said axis of rotation and longitudinally of said frame atleast partially in tension and compression,

said isolator means including a pair of resilient isolator membersconnecting each end of said roller to said frame,

one of said members being positioned forwardly of the rotational axis ofsaid roller and the other of said members being positioned rearwardly ofsaid axis,

at least one of said members connecting said roller to said frame in amanner so as to resist movements of said roller relative to said framealong the path of travel of said roller at least partially in tensionand compression.

3. Apparatus according to claim 2 wherein the rearwardly positioned oneof said isolator members resists longitudinal movements of said rollerrelative to said frame in tension and compression.

4. Apparatus according to claim 1 wherein said isolator means includesan isolator element mounted to resist axial movement of said rollerpartly in shear and partly in tension and compression.

5. Apparatus according to claim 2 wherein one of said pair of isolatormembers is mounted to resist longitudinal roller vibrations in tensionand compression and axial and vertical vibrations in shear, and theother of said isolator members is mounted to resist axial rollervibration in tension and compression and longitudinal vibrations inshear only.

6. Apparatus according to claim 2 wherein one of said pair of isolatormembers is mounted to resist both longitudinal and axial rollervibrations partly in tension and compression and partly in shear, andthe other of said isolator members is mounted to resist axial rollervibrations in tension and compression and longitudinal vibrations inshear only.

7. A vibratory compactor including:

a frame having a longitudinal dimension in the direction of travel ofsaid compactor,

a roller having an axis of rotation extending transversely Within saidframe,

vibrations generating means connected to said roller for vibrating saidroller,

and isolator means connecting the opposite ends of said roller to saidframe so as to isolate the frame from the vibrations of said roller,

said isolator means resisting vibrations of said roller in a directionnormal to said axis of rotation and longitudinally of said frame atleast partially in tension and compression,

said isolator means resisting longitudinal movements of said rollerrelative to said frame at least partly in tension and compression,vertical movements of said roller relative to said frame in shear, andaxial movements of said roller relative to said frame at least partly intension and compression.

8. A vibratory compactor comprising:

frame means,

a cylindrical drum roller within said frame means,

shaft means extending axially within said roller,

journal means journaling said shaft means to said frame means,

bearing means journaling said roller on said shaft means,

eccentric weight means on said shaft means having a center of gravityoffset from the rotational axis of said roller and driven by said shaftmeans,

power means on said frame means for rotating said shaft meansindependently of said roller so as to induce vibrations in said rollerin directions normal to the axis of rotation of said roller,

said journal means including journal support means and isolator meansconnecting said support means to said frame means in a manner providingresistance at least partially in tension and compression to vibrationsof said roller longitudinally in the direction of travel of saidcompactor,

said isolator means including resilient means resisting rollervibrations vertically in shear only and longitudinally partly in shearand partly in tension and compression in a manner such that saidresilient means offers a greater resistance to longitudinal vibrationsof said roller than to vertical vibrations thereof.

. A vibratory compactor including:

a frame having a longitudinal dimension in the direction of travel ofsaid compactor,

a roller having an axis of rotation extending transversely within saidframe,

vibrations generating means connected to said roller for vibrating saidroller,

and isolator means connecting the opposite ends of said roller to saidframe so as to isolate the frame from the vibrations of said roller,

said isolator means resisting vibrations of said roller in a directionnormal to said axis of rotation and longitudinally of said frame atleast partially in tension and compression,

said isolator means including at least two elastomer isolator members ateach end of said shaft means, one resisting longitudinal vibrations ofsaid roller in shear and the other resisting longitudinal vibrations ofsaid roller at least partly in tension and compresslon.

10. A vibratory compactor including:

a frame having a longitudinal dimension in the direction of travel ofsaid compactor,

a roller having an axis of rotation extending transversely within saidframe,

vibrations generating means connected to said roller for vibrating saidroller,

and isolator means connecting the opposite ends of said roller to saidframe so as to isolate the frame from the vibrations of said roller,

said isolator means resisting vibrations of said roller in a directionnormal to said axis of rotation and longitudinally of said frame atleast partially in tension and compression,

said isolator means including at least two elastomer isolator members ateach end of said shaft means, one resisting longitudinal vib ations ofsaid roller in shear only, the other resisting longitudinal vibrationsof said roller in tension and compression only. and both of saidisolator members resisting vertical vibrations of said roller in shearonly.

11. A vibratory compactor comprising:

frame means,

a cylindrical drum roller within said frame means,

shaft means extending axially within said roller,

journal means journaling said shaft means to said frame means,

bearing means journaling said roller on said shaft means,

eccentric weight means on said shaft means having a center of gravityoffset from the rotational axis of said roller and driven by said shaftmeans,

power means on said frame means for rotating said shaft meansindependently of said roller so as to induce vibrations in said rollerin directions normal to the axis of rotation of said roller,

said journal means including journal support means and isolator meansconnecting said support means to said frame means in a manner providingresistance at least partially in tension and compression to vibrationsof said roller longitudinally in the direction of travel of saidcompactor,

said shaft means having an axis of rotation offset from and parallel tothe axis of rotation of said roller in a direction tending to limit theamplitude of vibration transmitted from said shaft means to said journalmeans.

12. Apparatus according to claim 11 including means connected to saidshaft means for changing the degree of eccentricity of the rotationalaxis of said shaft means with respect to the rotational axis of saidroller.

13. A vibratory compactor comprising:

frame means,

a cylindrical drum roller within said frame means,

shaft means extending axially within said roller,

journal means journaling said shaft means to said frame means,

bearing means journaling said roller on said shaft means,

eccentric weight means on said shaft means having a center of gravityoffset from the rotational axis of said roller and driven by said shaftmeans,

power means on said frame means for rotating said shaft meansindependently of said roller so as to induce vibrations in said rollerin directions normal to the axis of rotation of said roller,

said journal means including journal support means and isolator meansconnecting said support means to said frame means in a manner providingresistance at least partially in tension and compression to vibrationsof said roller longitudinally in the direction of travel of saidcompactor,

said journal means mounting said shaft means for rotation about an axiswhich is eccentric with respect to the axis of rotation of said roller,

the rotational axis of said shaft means and the center of gravity ofsaid eccentric weight means being offset on the same side of therotational axis of said roller.

14. A vibratory compactor comprising:

frame means,

a cylindrical drum roller within said frame means,

shaft means extending axially within said roller,

journal means journaling said shaft means to said frame means,

hearing means journaling said roller on said shaft means,

eccentric weight means on said shaft means having a center of gravityoffset from the rotational axis of said roller and driven by said shaftmeans,

power means on said frame means for rotating said shaft meansindependently of said roller so as to induce vibrations in said rollerin directions normal to the axis of rotation of said roller,

said journal means including journal support means and isolator meansconnecting said support means to said frame means in a manner providingresistance at least partially in tension and compression to vibrationsof said roller longitudinally in the direction of travel of saidcompactor,

said frame means including a pair of laterally opposed side framemembers,

said roller being positioned between said side frame members,

said journal means including a hub portion containing a bearing for saidshaft means, a pair of support arms extending longitudinally in oppositedirections forwardly and rearwardly from said hub portion, an elastomerisolator member connecting a vertical face of one of said support armsto a parallel face of the adjacent said side frame member, with saidfaces extending normal to the rotational axis of said roller 1 so thatsaid isolator member resists longitudinal vibrations of said roller inshear,

a second elastomer isolator member connecting a vertical face of theother of said support arms to a parallel face of the adjacent said sideframe member, with said last-mentioned faces extending at an angle withrespect to said first-mentioned faces so that said second isolatormember resists longitudinal movement of said roller relative to saidside frame members at least partially in tension and compressron.

15. A vibratory compactor comprising:

a frame means,

a drum roller within said frame means,

shaft means journaled to said frame means for rotation about a firstaxis and connecting said roller to said frame means,

bearing means journaling said roller to said shaft means for rotationabout a second axis parallel to and olfset from said first axis,

and means connecting to said shaft means for varying the offset of saidsecond axis from said first axis.

16. A vibratory compactor according to claim 15- wherein said shaftmeans drives eccentric weight means rotatable with said shaft meansabout said first axis, the center of gravity of said eccentric weightmeans and said first axis being offset on the same side of said secondaxis.

References Cited UNITED STATES PATENTS 2,868,094 1/1959 Anderson 94-483,026,781 3/ 1962 Schafer 94-50 3,108,519 10/1963 Domenighetti 94503,225,669 12/1965 Green 94--5O NILE C. BYERS, JR., Primary Examiner

